Python Tutorial by Bernd Klein

Total Page:16

File Type:pdf, Size:1020Kb

Python Tutorial by Bernd Klein Python Tutorial by Bernd Klein bodenseo © 2021 Bernd Klein All rights reserved. No portion of this book may be reproduced or used in any manner without written permission from the copyright owner. For more information, contact address: [email protected] www.python-course.eu Python Course Python Tutorial by Bernd Klein Strings.......................................................................................................................................10 Execute a Python script ............................................................................................................11 Start a Python program.............................................................................................................12 Loops ......................................................................................................................................136 Iterators and Iterables .............................................................................................................150 Coffee, Dictionary and a Loop ...............................................................................................171 Parameters and Arguments.....................................................................................................226 Global, Local and nonlocal Variables.....................................................................................237 Regular Expressions ...............................................................................................................305 Lambda, filter, reduce and map ..............................................................................................340 content of test_foobar.py ........................................................................................................428 Deeper into Properties ............................................................................................................482 Descriptors..............................................................................................................................487 Multiple Inheritance: Example ...............................................................................................535 Polynomials ............................................................................................................................570 Metaclasses.............................................................................................................................597 Count Method Calls Using a Metaclass .................................................................................602 Abstract Classes......................................................................................................................607 2 HISTORY OF PYTHON EASY AS ABC What do the alphabet and the programming language Python have in common? Right, both start with ABC. If we are talking about ABC in the Python context, it's clear that the programming language ABC is meant. ABC is a general-purpose programming language and programming environment, which was developed in the Netherlands, Amsterdam, at the CWI (Centrum Wiskunde & Informatica). The greatest achievement of ABC was to influence the design of Python. Python was conceptualized in the late 1980s. Guido van Rossum worked that time in a project at the CWI, called Amoeba, a distributed operating system. In an interview with Bill Venners1, Guido van Rossum said: "In the early 1980s, I worked as an implementer on a team building a language called ABC at Centrum voor Wiskunde en Informatica (CWI). I don't know how well people know ABC's influence on Python. I try to mention ABC's influence because I'm indebted to everything I learned during that project and to the people who worked on it." Later on in the same Interview, Guido van Rossum continued: "I remembered all my experience and some of my frustration with ABC. I decided to try to design a simple scripting language that possessed some of ABC's better properties, but without its problems. So I started typing. I created a simple virtual machine, a simple parser, and a simple runtime. I made my own version of the various ABC parts that I liked. I created a basic syntax, used indentation for statement grouping instead of curly braces or begin-end blocks, and developed a small number of powerful data types: a hash table (or dictionary, as we call it), a list, strings, and numbers." COMEDY, SNAKE OR PROGRAMMING LANGUAGE So, what about the name "Python"? Most people think about snakes, and even the logo depicts two snakes, but the origin of the name has its root in British humour. Guido van Rossum, the creator of Python, wrote in 1996 about the origin of the name of his programming language1: "Over six years ago, in December 1989, I was looking for a 'hobby' programming project that would keep me occupied during the week around Christmas. My office ... would be closed, but I had a home computer, and not much else on my hands. I decided to write an interpreter for the new scripting language I had been thinking about lately: a descendant of ABC that would appeal to Unix/C hackers. I chose Python as a working title for the project, being in a slightly irreverent mood (and a big fan of Monty Python's Flying Circus)." THE ZEN OF PYTHON Beautiful is better than ugly. Explicit is better than implicit. Simple is better than complex. Complex is better than complicated. Flat is better than nested. HISTORY OF PYTHON 3 Sparse is better than dense. Readability counts. Special cases aren't special enough to break the rules. Although practicality beats purity. Errors should never pass silently. Unless explicitly silenced. In the face of ambiguity, refuse the temptation to guess. There should be one -- and preferably only one -- obvious way to d o it. Although that way may not be obvious at first unless you're Dutch. Now is better than never. Although never is often better than *right* now. If the implementation is hard to explain, it's a bad idea. If the implementation is easy to explain, it may be a good idea. Namespaces are one honking great idea -- let's do more of those! DEVELOPMENT STEPS OF PYTHON Guido Van Rossum published the first version of Python code (version 0.9.0) at alt.sources in February 1991. This release included already exception handling, functions, and the core data types of list, dict, str and others. It was also object oriented and had a module system. Python version 1.0 was released in January 1994. The major new features included in this release were the functional programming tools lambda, map, filter and reduce, which Guido Van Rossum never liked. Six and a half years later in October 2000, Python 2.0 was introduced. This release included list comprehensions, a full garbage collector and it was supporting unicode. Python flourished for another 8 years in the versions 2.x before the next major release as Python 3.0 (also known as "Python 3000" and "Py3K") was released. Python 3 is not backwards compatible with Python 2.x. The emphasis in Python 3 had been on the removal of duplicate programming constructs and modules, thus fulfilling or coming close to fulfilling the 13th law of the Zen of Python: "There should be one -- and preferably only one -- obvious way to do it." SOME CHANGES IN PYTHON 3.0: Print is now a function Views and iterators instead of lists The rules for ordering comparisons have been simplified. E.g. a het erogeneous list cannot be sorted, because all the elements of a lis t must be comparable to each other. There is only one integer type left, i.e. int. long is int as well. The division of two integers returns a float instead of an intege r. "//" can be used to have the "old" behaviour. Text Vs. Data Instead Of Unicode Vs. 8-bit HISTORY OF PYTHON 4 THE INTERPRETER, AN INTERACTIVE SHELL THE TERMS 'INTERACTIVE' AND 'SHELL' The term "interactive" traces back to the Latin expression "inter agere". The verb "agere" means amongst other things "to do something" and "to act", while "inter" denotes the spatial and temporal position to things and events, i.e. "between" or "among" objects, persons, and events. So "inter agere" means "to act between" or "to act among" these. With this in mind, we can say that the interactive shell is between the user and the operating system (e.g. Linux, Unix, Windows or others). Instead of an operating system an interpreter can be used for a programming language like Python as well. The Python interpreter can be used from an interactive shell. The interactive shell is also interactive in the way that it stands between the commands or actions and their execution. In other words, the shell waits for commands from the user, which it executes and returns the result of the execution. Afterwards, the shell waits for the next input. A shell in biology is a calcium carbonate "wall" which protects snails or mussels from its environment or its enemies. Similarly, a shell in operating systems lies between the kernel of the operating system and the user. It's a "protection" in both directions. The user doesn't have to use the complicated basic functions of the OS but is capable of using the interactive shell which is relatively simple and easy to understand. The kernel is protected from unintentional and incorrect usages of system functions. Python offers a comfortable command line interface with the Python Shell, which is also known as the "Python Interactive Shell". It looks like the term "Interactive Shell" is a tautology, because "shell" is interactive on its own, at least the kind of shells we have described
Recommended publications
  • Artificial Intelligence in Health Care: the Hope, the Hype, the Promise, the Peril
    Artificial Intelligence in Health Care: The Hope, the Hype, the Promise, the Peril Michael Matheny, Sonoo Thadaney Israni, Mahnoor Ahmed, and Danielle Whicher, Editors WASHINGTON, DC NAM.EDU PREPUBLICATION COPY - Uncorrected Proofs NATIONAL ACADEMY OF MEDICINE • 500 Fifth Street, NW • WASHINGTON, DC 20001 NOTICE: This publication has undergone peer review according to procedures established by the National Academy of Medicine (NAM). Publication by the NAM worthy of public attention, but does not constitute endorsement of conclusions and recommendationssignifies that it is the by productthe NAM. of The a carefully views presented considered in processthis publication and is a contributionare those of individual contributors and do not represent formal consensus positions of the authors’ organizations; the NAM; or the National Academies of Sciences, Engineering, and Medicine. Library of Congress Cataloging-in-Publication Data to Come Copyright 2019 by the National Academy of Sciences. All rights reserved. Printed in the United States of America. Suggested citation: Matheny, M., S. Thadaney Israni, M. Ahmed, and D. Whicher, Editors. 2019. Artificial Intelligence in Health Care: The Hope, the Hype, the Promise, the Peril. NAM Special Publication. Washington, DC: National Academy of Medicine. PREPUBLICATION COPY - Uncorrected Proofs “Knowing is not enough; we must apply. Willing is not enough; we must do.” --GOETHE PREPUBLICATION COPY - Uncorrected Proofs ABOUT THE NATIONAL ACADEMY OF MEDICINE The National Academy of Medicine is one of three Academies constituting the Nation- al Academies of Sciences, Engineering, and Medicine (the National Academies). The Na- tional Academies provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions.
    [Show full text]
  • Chapter 5 Names, Bindings, and Scopes
    Chapter 5 Names, Bindings, and Scopes 5.1 Introduction 198 5.2 Names 199 5.3 Variables 200 5.4 The Concept of Binding 203 5.5 Scope 211 5.6 Scope and Lifetime 222 5.7 Referencing Environments 223 5.8 Named Constants 224 Summary • Review Questions • Problem Set • Programming Exercises 227 CMPS401 Class Notes (Chap05) Page 1 / 20 Dr. Kuo-pao Yang Chapter 5 Names, Bindings, and Scopes 5.1 Introduction 198 Imperative languages are abstractions of von Neumann architecture – Memory: stores both instructions and data – Processor: provides operations for modifying the contents of memory Variables are characterized by a collection of properties or attributes – The most important of which is type, a fundamental concept in programming languages – To design a type, must consider scope, lifetime, type checking, initialization, and type compatibility 5.2 Names 199 5.2.1 Design issues The following are the primary design issues for names: – Maximum length? – Are names case sensitive? – Are special words reserved words or keywords? 5.2.2 Name Forms A name is a string of characters used to identify some entity in a program. Length – If too short, they cannot be connotative – Language examples: . FORTRAN I: maximum 6 . COBOL: maximum 30 . C99: no limit but only the first 63 are significant; also, external names are limited to a maximum of 31 . C# and Java: no limit, and all characters are significant . C++: no limit, but implementers often impose a length limitation because they do not want the symbol table in which identifiers are stored during compilation to be too large and also to simplify the maintenance of that table.
    [Show full text]
  • Beginning Portable Shell Scripting from Novice to Professional
    Beginning Portable Shell Scripting From Novice to Professional Peter Seebach 10436fmfinal 1 10/23/08 10:40:24 PM Beginning Portable Shell Scripting: From Novice to Professional Copyright © 2008 by Peter Seebach All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. ISBN-13 (pbk): 978-1-4302-1043-6 ISBN-10 (pbk): 1-4302-1043-5 ISBN-13 (electronic): 978-1-4302-1044-3 ISBN-10 (electronic): 1-4302-1044-3 Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1 Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. Lead Editor: Frank Pohlmann Technical Reviewer: Gary V. Vaughan Editorial Board: Clay Andres, Steve Anglin, Ewan Buckingham, Tony Campbell, Gary Cornell, Jonathan Gennick, Michelle Lowman, Matthew Moodie, Jeffrey Pepper, Frank Pohlmann, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Project Manager: Richard Dal Porto Copy Editor: Kim Benbow Associate Production Director: Kari Brooks-Copony Production Editor: Katie Stence Compositor: Linda Weidemann, Wolf Creek Press Proofreader: Dan Shaw Indexer: Broccoli Information Management Cover Designer: Kurt Krames Manufacturing Director: Tom Debolski Distributed to the book trade worldwide by Springer-Verlag New York, Inc., 233 Spring Street, 6th Floor, New York, NY 10013.
    [Show full text]
  • Scala Tutorial
    Scala Tutorial SCALA TUTORIAL Simply Easy Learning by tutorialspoint.com tutorialspoint.com i ABOUT THE TUTORIAL Scala Tutorial Scala is a modern multi-paradigm programming language designed to express common programming patterns in a concise, elegant, and type-safe way. Scala has been created by Martin Odersky and he released the first version in 2003. Scala smoothly integrates features of object-oriented and functional languages. This tutorial gives a great understanding on Scala. Audience This tutorial has been prepared for the beginners to help them understand programming Language Scala in simple and easy steps. After completing this tutorial, you will find yourself at a moderate level of expertise in using Scala from where you can take yourself to next levels. Prerequisites Scala Programming is based on Java, so if you are aware of Java syntax, then it's pretty easy to learn Scala. Further if you do not have expertise in Java but you know any other programming language like C, C++ or Python, then it will also help in grasping Scala concepts very quickly. Copyright & Disclaimer Notice All the content and graphics on this tutorial are the property of tutorialspoint.com. Any content from tutorialspoint.com or this tutorial may not be redistributed or reproduced in any way, shape, or form without the written permission of tutorialspoint.com. Failure to do so is a violation of copyright laws. This tutorial may contain inaccuracies or errors and tutorialspoint provides no guarantee regarding the accuracy of the site or its contents including this tutorial. If you discover that the tutorialspoint.com site or this tutorial content contains some errors, please contact us at [email protected] TUTORIALS POINT Simply Easy Learning Table of Content Scala Tutorial ..........................................................................
    [Show full text]
  • A First Course to Openfoam
    Basic Shell Scripting Slides from Wei Feinstein HPC User Services LSU HPC & LON [email protected] September 2018 Outline • Introduction to Linux Shell • Shell Scripting Basics • Variables/Special Characters • Arithmetic Operations • Arrays • Beyond Basic Shell Scripting – Flow Control – Functions • Advanced Text Processing Commands (grep, sed, awk) Basic Shell Scripting 2 Linux System Architecture Basic Shell Scripting 3 Linux Shell What is a Shell ▪ An application running on top of the kernel and provides a command line interface to the system ▪ Process user’s commands, gather input from user and execute programs ▪ Types of shell with varied features o sh o csh o ksh o bash o tcsh Basic Shell Scripting 4 Shell Comparison Software sh csh ksh bash tcsh Programming language y y y y y Shell variables y y y y y Command alias n y y y y Command history n y y y y Filename autocompletion n y* y* y y Command line editing n n y* y y Job control n y y y y *: not by default http://www.cis.rit.edu/class/simg211/unixintro/Shell.html Basic Shell Scripting 5 What can you do with a shell? ▪ Check the current shell ▪ echo $SHELL ▪ List available shells on the system ▪ cat /etc/shells ▪ Change to another shell ▪ csh ▪ Date ▪ date ▪ wget: get online files ▪ wget https://ftp.gnu.org/gnu/gcc/gcc-7.1.0/gcc-7.1.0.tar.gz ▪ Compile and run applications ▪ gcc hello.c –o hello ▪ ./hello ▪ What we need to learn today? o Automation of an entire script of commands! o Use the shell script to run jobs – Write job scripts Basic Shell Scripting 6 Shell Scripting ▪ Script: a program written for a software environment to automate execution of tasks ▪ A series of shell commands put together in a file ▪ When the script is executed, those commands will be executed one line at a time automatically ▪ Shell script is interpreted, not compiled.
    [Show full text]
  • A Call-By-Need Lambda Calculus
    A CallByNeed Lamb da Calculus Zena M Ariola Matthias Fel leisen Computer Information Science Department Department of Computer Science University of Oregon Rice University Eugene Oregon Houston Texas John Maraist and Martin Odersky Philip Wad ler Institut fur Programmstrukturen Department of Computing Science Universitat Karlsruhe UniversityofGlasgow Karlsruhe Germany Glasgow Scotland Abstract arguments value when it is rst evaluated More pre cisely lazy languages only reduce an argument if the The mismatchbetween the op erational semantics of the value of the corresp onding formal parameter is needed lamb da calculus and the actual b ehavior of implemen for the evaluation of the pro cedure b o dy Moreover af tations is a ma jor obstacle for compiler writers They ter reducing the argument the evaluator will remember cannot explain the b ehavior of their evaluator in terms the resulting value for future references to that formal of source level syntax and they cannot easily com parameter This technique of evaluating pro cedure pa pare distinct implementations of dierent lazy strate rameters is called cal lbyneed or lazy evaluation gies In this pap er we derive an equational characteri A simple observation justies callbyneed the re zation of callbyneed and prove it correct with resp ect sult of reducing an expression if any is indistinguish to the original lamb da calculus The theory is a strictly able from the expression itself in all p ossible contexts smaller theory than the lamb da calculus Immediate Some implementations attempt
    [Show full text]
  • Php Foreach Array Example
    Php Foreach Array Example Positivism Sonnie always besought his dimeters if Esme is fruticose or touch-types incompletely. Sometimes anything.plenipotentiary Zane Gordieemits unobtrusively alchemise her while foreman untrained slower, Harlan but bubbliest presages Rodge obsoletely strides or pippingriotously masterfully. or recapitalizes You can have explored deep are using array_map prevents you forgot, and will keep multiple. How we have an associative array is a different values are times has a numeric array and arrays can be obtained by working along. This url into two variables are such type. PHP 4 introduced foreach construct it works only on arrays. Let's understand this with the help bear the porter example. The running one uses it. PHP foreach Manual. Sample PHP Code PHP For Loops Foreach While ago Do. Arrayvalue is your temporary variable that holds the current total item values block of code is the its of code that operates on already array values Example 1. Usually depending on my favourite site for passing it on how if statement. PHP foreach loops FreeKB. Start from any one statement is that, instead of items in an example of each elements with examples to get an array. PHP foreach within foreach repeat data flow not escaping loops. Of iteration helps you can access or public route on here? PHP foreach Loop GeeksforGeeks. Foreach Semantic portal learn smart. Nested for loops One for brother can be no inside another for purpose and force can generate different scripts using nested loops Here is an intelligence for. Here there is used in a block on array index or break statement or associative array by using a multidimensional array an.
    [Show full text]
  • PHP String Interview Questions
    By OnlineInterviewQuestions.com String Interview Questions in PHP Q1. What is String in PHP? The String is a collection or set of characters in sequence in PHP. The String in PHP is used to save and manipulate like an update, delete and read the data. Q2. How to cast a php string to integer? The int or integer used for a variable into an integer in PHP. Q3. How to perform string concatenation in PHP? The string concatenation means two strings connect together. The dot ( . ) sign used in PHP to combine two string. Example:- <?php $stringa = " creative "; $stringb = "writing "; echo $stringa . $stringb; ?> Q4. How to get php string length? To determine the string length in PHP, strlen() function used. Example:- echo strlen(“creative writing”); Q5. List some escape characters in PHP? Some list escape characters in PHP there are:- \’ \” \\ \n \t \r Q6. How to convert special characters to unicode in php? There is function json_encode() which is converted special characters to Unicode in PHP. Example:- $stringa = " I am good at smiling"; print_r(json_encode($stringa)); Q7. How to add double quotes in string in php? The double quotes in string using (" ") sign and write content under this sign. The double quotes convert variable as value. An example is below:- $str8 = " need to read data where has to go "; echo $str 8output: double quotes in the string echo “ PHP work $str8 output: PHP work need to read data where has to go Q8. Explain how php string interpolation is done? The interpolation is adding variables in among a string data. PHP parses the interpolate variables and replaces this variable with own value while processing the string.
    [Show full text]
  • "This Book Was a Joy to Read. It Covered All Sorts of Techniques for Debugging, Including 'Defensive' Paradigms That Will Eliminate Bugs in the First Place
    Perl Debugged By Peter Scott, Ed Wright Publisher : Addison Wesley Pub Date : March 01, 2001 ISBN : 0-201-70054-9 Table of • Pages : 288 Contents "This book was a joy to read. It covered all sorts of techniques for debugging, including 'defensive' paradigms that will eliminate bugs in the first place. As coach of the USA Programming Team, I find the most difficult thing to teach is debugging. This is the first text I've even heard of that attacks the problem. It does a fine job. Please encourage these guys to write more." -Rob Kolstad Perl Debugged provides the expertise and solutions developers require for coding better, faster, and more reliably in Perl. Focusing on debugging, the most vexing aspect of programming in Perl, this example-rich reference and how-to guide minimizes development, troubleshooting, and maintenance time resulting in the creation of elegant and error-free Perl code. Designed for the novice to intermediate software developer, Perl Debugged will save the programmer time and frustration in debugging Perl programs. Based on the authors' extensive experience with the language, this book guides developers through the entire programming process, tackling the benefits, plights, and pitfalls of Perl programming. Beginning with a guided tour of the Perl documentation, the book progresses to debugging, testing, and performance issues, and also devotes a chapter to CGI programming in Perl. Throughout the book, the authors espouse defensible paradigms for improving the accuracy and performance of Perl code. In addition, Perl Debugged includes Scott and Wright's "Perls of Wisdom" which summarize key ideas from each of the chapters, and an appendix containing a comprehensive listing of Perl debugger commands.
    [Show full text]
  • IEEE Standard 754 for Binary Floating-Point Arithmetic
    Work in Progress: Lecture Notes on the Status of IEEE 754 October 1, 1997 3:36 am Lecture Notes on the Status of IEEE Standard 754 for Binary Floating-Point Arithmetic Prof. W. Kahan Elect. Eng. & Computer Science University of California Berkeley CA 94720-1776 Introduction: Twenty years ago anarchy threatened floating-point arithmetic. Over a dozen commercially significant arithmetics boasted diverse wordsizes, precisions, rounding procedures and over/underflow behaviors, and more were in the works. “Portable” software intended to reconcile that numerical diversity had become unbearably costly to develop. Thirteen years ago, when IEEE 754 became official, major microprocessor manufacturers had already adopted it despite the challenge it posed to implementors. With unprecedented altruism, hardware designers had risen to its challenge in the belief that they would ease and encourage a vast burgeoning of numerical software. They did succeed to a considerable extent. Anyway, rounding anomalies that preoccupied all of us in the 1970s afflict only CRAY X-MPs — J90s now. Now atrophy threatens features of IEEE 754 caught in a vicious circle: Those features lack support in programming languages and compilers, so those features are mishandled and/or practically unusable, so those features are little known and less in demand, and so those features lack support in programming languages and compilers. To help break that circle, those features are discussed in these notes under the following headings: Representable Numbers, Normal and Subnormal, Infinite
    [Show full text]
  • NU-Prolog Reference Manual
    NU-Prolog Reference Manual Version 1.5.24 edited by James A. Thom & Justin Zobel Technical Report 86/10 Machine Intelligence Project Department of Computer Science University of Melbourne (Revised November 1990) Copyright 1986, 1987, 1988, Machine Intelligence Project, The University of Melbourne. All rights reserved. The Technical Report edition of this publication is given away free subject to the condition that it shall not, by the way of trade or otherwise, be lent, resold, hired out, or otherwise circulated, without the prior consent of the Machine Intelligence Project at the University of Melbourne, in any form or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent user. The Machine Intelligence Project makes no representations or warranties with respect to the contents of this document and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. Furthermore, the Machine Intelligence Project reserves the right to revise this document and to make changes from time to time in its content without being obligated to notify any person or body of such revisions or changes. The usual codicil that no part of this publication may be reproduced, stored in a retrieval system, used for wrapping fish, or transmitted, in any form or by any means, electronic, mechanical, photocopying, paper dart, recording, or otherwise, without someone's express permission, is not imposed. Enquiries relating to the acquisition of NU-Prolog should be made to NU-Prolog Distribution Manager Machine Intelligence Project Department of Computer Science The University of Melbourne Parkville, Victoria 3052 Australia Telephone: (03) 344 5229.
    [Show full text]
  • A Style Guide
    How to Program Racket: a Style Guide Version 6.11 Matthias Felleisen, Matthew Flatt, Robby Findler, Jay McCarthy October 30, 2017 Since 1995 the number of “repository contributors” has grown from a small handful to three dozen and more. This growth implies a lot of learning and the introduction of inconsistencies of programming styles. This document is an attempt leverage the former and to start reducing the latter. Doing so will help us, the developers, and our users, who use the open source code in our repository as an implicit guide to Racket programming. To help manage the growth our code and showcase good Racket style, we need guidelines that shape the contributions to the code base. These guidelines should achieve some level of consistency across the different portions of the code base so that everyone who opens files can easily find their way around. This document spells out the guidelines. They cover a range of topics, from basic work (commit) habits to small syntactic ideas like indentation and naming. Many pieces of the code base don’t live up to the guidelines yet. Here is how we get started. When you start a new file, stick to the guidelines. If you need to edit a file, you will need to spend some time understanding its workings. If doing so takes quite a while due to inconsistencies with the guidelines, please take the time to fix (portions of) the file. After all, if the inconsistencies throw you off for that much time, others are likely to have the same problems.
    [Show full text]